<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
  <input type="text" placeholder="height(m)" v-model="h">
  <input type="text" placeholder="weight(kg)" v-model="w">
  <input type="button" value="Test" @click="f()">
  <h3>Result:{{result}}</h3>
</div>
<script src="https://cdn.bootcdn.net/ajax/libs/axios/0.21.1/axios.min.js"></script>
<script src="https://cdn.staticfile.org/vue/2.6.14/vue.min.js"></script>
<script>
  let v = new Vue({
    el:"body>div",
    data:{
      result:"",
      h:"",
      w:""
    },
    methods:{
      f() {
        axios.get("/bmi?h="+v.h+"&w="+v.w).then(function (response) {
          v.result = response.data;
        })
      }
    }
  })

</script>
</body>
</html>